The need is to use a bipolar + & - 10v analog signal from two Mach4 DRO axes to tell the servos to move.

Why do you need analogue voltages?

Most modern servos can still be driven by an analogue voltage but that requires a feedback capable motion controller.In this setup the encoder is still hooked to the servo drive, as I explained earlier the encoder is required by the driveto compose it output. The encoder, or some derived signal from it, is outputted to the controller. The controllercloses the loop. The controller outputs a precision analogue voltage and the servo turns at a speed determined by thevoltage. The servo is in velocity mode.

The same servo could be in position mode. In this set up the position is commanded by Mach4/Galill as a series ofstep/direction pulses. The servo drive accumulates those pulses and therefore knows where is it supposed to be.It compares where it supposed to be to where it actually is (by the encoder) and drives the servo accordingly.The PID tuning is done entirely within the servo drive. The controller has no need of the encoder signal at all.

If Mach4 decides that it needs to drive an axis 100mm in the +direction it will plan the trajectory as a series ofP(osition)V(elocity)over T(ime) data packets in 1 ms slices. The motion controller will convert the PVT data to step/directionpluses for all servos.

At the beginning of the move Mach will plan to accelerate the axis smoothly before reaching it ultimate speed. The servoand drive are assumed to be capable of the acceleration and ultimate speed required. If the servo can't keep up with the planned trajectory then the drive will fault 'following error'.

In this way Mach4/Gallil are an open loop controller only. It provides the trajectory which is converted to step direction pulsesand the servo just goes there. If it can't it will signal that with a following error fault. This is a more modern control setup. It meansthat the motion controller does not have to be feedback capable. The only feedback capable controllers that work with Mach4(Gallil, Hicon Integra, CSMIO/A) are all expensive, the cheapest is 600Euro. By comparison the plain open loop step/directionmotion controllers (Ethernet SmoothStepper, UC300, UC00, UC100,57CNC, 57CNCdb25,PMDX-411, PMDX-242) range from$120 to $250.

The Ethercat solution which is being developed for Mach4 requires two pieces of software for your PC only. RTX64 byInterval Zero provides a realtime core capability to your non-realtime Windows PC and KingStar provide the pluginthat makes Mach4 an Ethercat Master. The servo drives (all Ethercat slaves) are connected by a daisy chain of Ethernetcables.......and that's it. No expensive hardware controller required!

You may have noticed that you can hook limit switches to your drive, you don't have to hook them to the controller at all.The servo drive is smart enough to handle that. It is in fact a required feature that any servo drive must be able to doif it is ever to be Ethercat slave capable. That is to say that the servo can act autonomously.

Most modern servos can still be driven by an analogue voltage but that requires a feedback capable motion controller.In this setup the encoder is still hooked to the servo drive, as I explained earlier the encoder is required by the driveto compose it output. The encoder, or some derived signal from it, is outputted to the controller. The controllercloses the loop. The controller outputs a precision analogue voltage and the servo turns at a speed determined by thevoltage. The servo is in velocity mode.

Good question. I'm stepping in to someone else's configuration of parts and pieces that thus far are not working with a 20 year old Galil DMC-2130 controller using its ICM-1900 breakout board. The 2 servo drives: Kollmorgen S20360 and S20260, the 2 3 phase high AC servos: Kollmorgen AKM42G-BKCN2-01 and AKM-BNBN1-00. Both of these drivers can access digital or analog velocity signals. Analog velocity signals can be differential or single-end, bipolar. If the drives are enabled they should respond to their analog velocity input.

There is no external controller (that we know of) that works with these drivers and servos and Mach4. I'm very familiar with Mach3 but new to Mach4 as of 4 days ago.

The servos and drives work great for the most part when controlled by Kollmorgen's OC Tools Windows app communicating via RS-232 between PC and Drivers. Each servo encoder feeds back to it respective driver. Control is "digital" in this scenario using the OC Tools app for tuning, etc. Each driver "offers" additional access to the 6 encoder signals for Ch. A, B and Index from each driver through a mass termination connector. Presently, these "auxiliary" encoder connections are connected to the X and Z axis encoder inputs on the ICM-1900 terminal block which feeds into the DCM-2130 controller. I am hoping this is what you mean when you say

Quote

The encoder, or some derived signal from it, is outputted to the controller.

BTW: This DCM controller's servo driver boards are disabled and not used to drive any servos.

The DCM connects via Ethernet to the Mach4 PC's isolated Ethernet LAN via TCP/IP. With the Mach4 Galil Plugin and Galil Tools installed that provide s TCP communications between the plugin and the DCM very basic communications are confirmed in that the plugin "detects" the DCM by IP address, allows the DCM to become a "registered" device and thereby allows access to the Galil device configuration screens.

No, the author of the plugin states that the Mach4 Galil Plugin may or may not work with the DCM-2130 even though it did with the Mach3 Galil Plugin.

So, we are optimistically hopeful the plugin works. But first, making sure Mach4 is setup correctly with the servo/encoder scenario is my first priority.